After watching the promotional videos its clear to me that Apple’s Aperture photo management / post editing software is best-of-breed. The demos are simply impressive.
I liked their method of photo “version control”. It always keeps the original photo intact and all changes are new versions (where only the changed data stored). This allows you to work with photos in RAW format from the shoot to post editing yet it will not take much hd space to have hundreds of revisions of a particular photo. Check out this demo